Method of manufacturing pressure cylinders



e. M. GEIGER ET AL Original Filed March 6, 1944 f-gW lama a METHOD OF MANUFACTURING PRESSURE CYLINDERS Aug. 9, 1949.

Patented Aug. 9, 1949 METHOD OF MANUFACTURING PRESSURE CYLINDERS George M. Geiger and Harold A. Donncnwlrth,

Mount Gilead, Ohio, assignors to H-P-M Development Corporation, Wilmington, Del.,' a

corporation of Delaware Original application March 6, 1944, serial No. 525,258. Divided and this application August 11, 1945, Serial No. 610,304

4 Claims.

This invention relates to a method of manufacturing pressure cylinders. More particularly, this invention relates to a method of manufacturing pressure cylinders of greater than average length.

In many instances such as hydraulically operated machine tools having a long table travel a pressure cylinder of considerable length is required. The casting, handling and machining of these cylinders is sometimes diflicult on account of the space requirements necessary. Furthermore, an imperfection in the casting or an inaccuracy in the machining results in the loss of the completeunit.

The primary object of the present invention is to provide a method of making long pressure cylinders of short segments or sections whereby the aforementioned difiiculties are overcome.

It is another object of this invention to provide an improved method of sealing between the various portions of a sectional cylinder.

It is still another object of the present invention to provide a method of constructing such a cylinderwherein the various portions are accurately axially aligned.

This is a division of our co-pending application Serial No. 525,258, filed March 6, 1944, issued as Patent No. 2,443,312 on June 15, 1948.

These and other objects will become more apparent upon reference to the following description taken in connection with the attached drawings, in which:

Figure 1 is a view of a pressure cylinder constructed according to this invention and mounted in the bed of a machine tool, and

Figure 2 is an enlarged longitudinal vertical section through the said cylinder, and

Figure 3 is a view showing a joint between adjacent portions of the cylinder before the said portions are completely assembled, and

Figure 4 is a view similar to Figure 3 showing the adjacent portions completely assembled.

General arrangement According to this invention a plurality of relatively short cylinder segments are provided and are assembled end to end to form a long and completed pressure cylinder. Suitable sealing means are provided where each portion joins the next so that leakage therebetween is substantially eliminated. According to this invention the sealing means includes a metal to metal contact and in it is desired to assemble, the internal surface of the cylinder is ground or honed so that the complete structure is fluid tight and has an axially accurate bore therethrough.

For use as an element in a hydraulic power system, suitable closure caps are provided for each end of the assembled cylinder and the ram means may be reciprocably mounted therein.

Detailed description Referring now to Figure 1 there is shown a machine tool such as a grinder or planer having a reciprocating work holding table at l0 which is slidably mounted on a bed H. Carried by the table 10 is a work piece 12 which it is desired to reciprocate beneath a machining tool l3.

Mounted in the bed I l is a hydraulic pressure cylinder generally indicated at M and comprising a plurality of segments l 5, l 6 and H. 'An end cap or closure plate I 8 is provided at the right end of the cylinder and a similar member l9 at the left end. The closure member [9 is apertured to receive the piston rod 20 which is attached by means of a lug or bracket 2| to the table Ill. The rod 20 also comprises a piston portion 22 reciprocable within the cylinder I4. Fluid communication is had with the interior of the cylinder through the conduits 23 and 24, the former entering the cylinder through the closure member 18 and the latter entering the cylinder through the segment Il. Pressure fluid is supplied in any well known manner to the conduits 23 and 24 thereby to reciprocate the piston 22 therein and, hence, also to reciprocate the rod 20 and the table It).

Referring now to Figure 2 the construction of the cylinder 14 is more particularly shown. The segment l5 has bolted to the right end thereof the closure member l8 by any suitable means such as the cap screws 25. The member 18 also includes an inwardly extending annular ring portion 28 which, externally, closely fits within the bore 26 of the segment [5. A groove 21 around the annular portion 28 is adapted to receive a ring of yielding sealing material so as substantially completely to prevent leakage of fluid from the inside of the cylinder to the outside.

The right end cylinder segment l5 terminates in an enlarged bore 29, best seen in Figures 3 and 4. The enlarged bore 29 includes a shoulder 30, a straight bore 3| and a threaded portion 32. The bore 3| preferably has a diameter slightly less than the peak diameter of the threaded portion 32 for a purpose which will become more ap- Parent hereinafter. The above described enlarged bore forms the female portion of the joint aligning adjacent segments and, by means of the threaded portion 32 the means for retaining the said adjacent segments together.

The right end of the adjacent cylinder section or segment I6, terminates in a male portion adapted to cooperate with the female portion of the segment I in order to, seals. alignpand reta n the segments in proper association. The right end of the segment I6, which is adapted to cooperate with the bore in the left endof'the segment i5, is;

a reduced diameter portion" including a threaded portion 33 adapted to cooperate with the threads 32 on I5, a pilot portion 34 adapted to be 138- ceived within the straight bore portion 3I of section I5 and, an axially outwardly. projecting. V-

shaped end or ti 35which is adapted to; co p a with the shoulder in section I 5' so as to pr vide the aforementioned metal to, metal Contact Cylinder. segments are assembled as shown in Figure 3 by threading the portion 33 of I6" into the threaded portion 32: of I5. A sealing ring 36 is placed on the shoulder 30' to be retained thereon by the v-shaped tip 35. The cylinder segments are threaded together was to compress the sealing ring 36, as shown in Figure 4, and also to cause the V-shapedtip to abut the shoulder 30. Preferably, the segments I5 and I6 are threaded together. sufllcientlytightly so that a slight deformation of the'shoulder 30 and the tip 35 is effected at the point of abutment thereof.

The segment I6 terminates at its left end in a female portion substantially identical with that of the left end of section I5. Hence, as many segments as it is desired to assemble may be joined together end to end.

When the segments have been assembled'the completed unit is internally ground or honed by a suitable abrasive means. such as is indicated at 31 inFigure 4 thereby to provide the unit with a straight, smooth and accurate internal bore. 7

The left end segment I! orthe cylinder M. has, at its right end, a male portion substantially identical with that of the segment. I5 and, at its left end has a threaded portion adapted to r ceive the closure member. I9. The. closure member I9 is provided with an. annular. groove 2 which containspacking material and provides a seal against leakage. of fluid from the interior of the cylinder.

The member I9 is apertured. to receive thepiston rod 20 and is provided'with theusual bushin 39, packing 40 and packing retaining means 4|. The member I9 also includes an inwardly extending annular portion 42 which .is radially aperturedas at 43. Adapted closely to fit within the sleeve 42 is a reduced diameter portion 44 on the piston 22. The arrangement. is such that, ,as the piston 22 approaches the left end of the cylinder I4, the reduced diameter portion 44 will enter the sleeve 42, trapping fluidtherein and forcing the same outwardly through the apertures 43 thereby cushioning the final portion of the stroke of thepiston 22 and preventing the same from forcibly striking the'closure member I 9.

The right end of the piston 22 includes a sleeve portion 45 having therein radial apertures 46. The sleeve '45 is adapted to cooperate with the annular portion 28 of the closure member I8 so as'to cushion'the .end part of the rightward movement of the piston 22 in the same manner as de- 4 scribed hereinbefore in connection with the portion 44 and with the sleeve 42.

The various segments may be locked together. after assembly, by means of; escrow which is threaded into a hole which is drilled and threaded subsequent to the said assembly of the various segments. However, the adjoining parts of the segments maybe, so formed that they abut externally as well as internally. That is, the space 5I in Figure 4 could be eliminated by properly forming thesegments I5 and I6 so as to abut at that point.

.Itwill be understood that various modifications could be made in the structure shown without departing from the spirit of the invention and hence we do not Wish to be limited to the specific structure shown and described but desire to comprehend such modifications as come within the scope of the appended claims.

We claim; v

I; A) method of manufacturing relatively long pressure cylinders. which comprises, subdividing the said cylinder into a plurality of relatively short axially bored sections, forming a cylindrical projection on one end of each of said sections and a cylindrical counterbore in the other end, said projection and counterbore having their axes parallel with the axis of th bore in the associated section, arranging the said sections end to end with the counterbores telescoping wi h said projections. provid n cooperat n shoulders on the abutting end of said projection and counter ores adjacent th bores ther which abut when saidsectious aresecured toeether so as to provide a substantially. continuous bore through sai a s mbled sections, securing said sections together, with sufilcipnt axial thrust to deform said shoulders in theabseme of heat, effecting a circumferential seal between adjoining sections, and grindingthe hereof the assemblyto. remove a thin. layer from the bores of said sections and toremove the protuberant ridges formed by the deformation of said shoulders. thereby to produce a substantially straight and accurate bore throu h the assembly.

2. A method of manufacturing relatively long pressure cylinders which comprises, subdividing the said cylinder into a plurality of relatively sh t axially bored sections. turning a cy indr ca projection on one end of each section and counterboring a cylindrical recess in the other end, screw threading he base part of said projection and the outer part of said recess, arranging said sections in end to end relationship with the bores thereof substantially in axial alignment, and with the projection of each section telescoping the recess of the next adjacent section, threading said sections together so sufficient axial thrust is developed to cause at-least a slight inwardly extending circumferential deformation thereof at the point of abutment, and in the absence of heat, and machine working the bore of the assembled unit to remove said deformations and a thin surface layer from the entire, bore so as to produce a continuous bore of the desired accuracy throughout the length of the said assembled unit.

3. The method of securing axially bored cyl inder sections together which comprises, forming a cylindrical p ojection on th endof one of said sections coaxial with the bore of the Section, forming a cylindrical recess in .theadjacmt end of the other section coaxial with the bore of the said o her se tion and adap d lose to ceive said projection and being of less axial length than said projection, screw threading a portion of said projection from the base thereof toward the end and a portion of said recess from the open end thereof toward the bottom, chamfering the extended unthreaded end of said projection to provide a recess for receivin a sealing member between the end of the Projection and the corner at the bottom of the recess and also to provide a reduced area portion on the end of said projection, screw threading said sections together with sufficient tightness that enough axial thrust is generated therebetween to slightly deform the chamfered end of said projection and the abutting portion of the other section, and machine working the assembled unit to produce an axially straight and smooth bore.

4. The method of securing axially bored cylinder sections together which comprises, forming a cylindrical projection on the end of one of said sections, forming a cylindrical recess in the adjacent end of the other section adapted closely to receive said projection and being of less axial length than said projection, said projection and recess being coaxial with the bores of the sections, screw threading a portion of the length of said projection adjacent the bore thereof and a portion of the length of said recess adjacent the open end thereof, chamfering the extended end of said projection to provide a recess for receiving a sealin member between the end of said projection and the corner at the bottom of said recess and also to provide a reduced area portion on the end of said projection, screw threading said sections together with sufficient tightness to generate enough axial thrust therebetween to slightly deform the chamfered end of said projection and the abutting portion of the other section, positively locking the sections together, and machine working th assembled unit to provide an axially straight and smooth bore.

GEORGE M. GEIGER.

H. A. DONNENWIRTH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 932,914 Shoptaw Aug. 31, 1909 1,011,803 Jones Dec. 12, 1911 1,219,139 Murray Mar. 13, 1917 1,396,243 Beloit Nov. 8, 1921 2,055,296 Lane Sept. 22, 1936 2,062,407 Eaton Dec. 1, 1936 2,112,108 Mackenzie Mar. 22, 1938 2,125,106 Gehret July 26, 1938 2,144,928 Moncriefi' Jan. 24, 1939 2,187,217 Winslow Jan. 16, 1940 2,235,070 Giern Mar. 18, 1941 2,257,355 Evans Sept. 30, 1941 2,365,162 Abrams Dec. 19, 1944 FOREIGN PATENTS Number Country Date 539,139 Great Britain Aug. 28, 1941 

